Comparative study of I–V characteristics of “metal-semiconductor-metal” structures without coatings and with protective coatings is presented. Regimes for radio frequency deposition of dielectric coatings on the surface of pixeled Schottky junction based on Cl-doped CdTe single crystals with high resistivity (10 7 –10 10 ) Ω·cm were determined. In particular, the films with composition of (TeO 2 ) x –(SiO 2 ) 1−x have demonstrated high isolation properties. Possible applications of new CdTe pixeled detectors with the studied protective coatings for high resolution spectrometry in X- and gamma-ray sensor devices are discussed.